The present invention disclosed herein relates to a multi-core device, a test device, and a method of diagnosing failure.
Even if some cores fail among a plurality of cores, a multi-core device blocks the corresponding failed cores in a system so as not to affect the remaining normal cores and to operate normally. Accordingly, the multi-core device determines failed cores through an accurate failure diagnosis and replaces them with normal cores or blocks them. While taking some performance loss into account, the multi-core device may be used.
A homogeneous multi-core device diagnoses a plurality of cores in parallel by applying the same test pattern value and thus test costs are reduced. However, even if the same test pattern value is applied, a test response value outputted from each core may vary depending on whether a core fails.
A typical multi-core device failure diagnosis uses an on-chip comparator for testing a core by comparing a test response value of a core and an expected value to text a core. If no failure occurs, since it is expected that a plurality of cores output the same test response value with respect to the same test pattern value, the plurality of cores may be tested in parallel by comparing an expected value and a test response value of a corresponding core for each core through a comparator.
However, in order to transmit expected values from the inside to the outside of a chip, additional test pins are required for a test device and a test target chip. Therefore, the increased number of test pins may cause a rise in the test costs.